Whiteline Front Roll Centre & Bump Steer Correction Kit - Subaru WRX 02-07 / STI 04-09 / Legacy GT 05-08 / WRX Hatch 08+ (KCA313)

Restore correct front suspension geometry on your lowered Subaru with the Whiteline front roll centre and bump steer correction kit. The KCA313 is a must-have upgrade for any lowered WRX, STI, Legacy GT, or WRX Hatch — using specially engineered ball joints and tie rod ends to raise the front roll centre back toward its factory design height, correcting the geometry errors introduced by lowering the vehicle and delivering a substantial improvement in front end grip, cornering speed, and handling consistency.

Note: Designed for lowered vehicles. On vehicles at factory ride height, roll centre correction may not be necessary. Verify your specific lowering amount and geometry requirements before ordering.

Key Features:

• Corrects front roll centre geometry on lowered vehicles
• Corrects bump steer introduced by lowering
• Specially engineered ball joints and tie rod ends
• Raises front roll centre toward factory design height
• Fits 2002-2007 Subaru WRX, 2004-2009 STI, 2005-2008 Legacy GT, 2008+ WRX Hatch
• Whiteline quality and engineering
• 4.6 lbs

Performance Benefits:

• Raised Front Roll Centre: Correcting the roll centre substantially increases front roll resistance, reducing body roll in corners without requiring stiffer springs or anti-roll bars
• Reduced Outside Wheel Compression: Raising the roll centre significantly reduces suspension compression of the outside front wheel during cornering, keeping the tyre more upright and maximizing contact patch
• More Even Weight Distribution: Corrected roll centre geometry provides more balanced weight transfer across all four tyres during cornering
• Improved Tyre Contact: More even weight distribution and reduced outside wheel compression improves tyre contact patch, increasing front end grip
• Bump Steer Correction: Corrects the toe change through suspension travel (bump steer) introduced by lowering, providing more predictable steering response over bumps and mid-corner
• Improved Cornering Speed: The combined effect of roll centre correction and bump steer elimination allows higher cornering speeds with more confidence and consistency

Specifications:

• Brand: Whiteline
• Part Number: KCA313
• Components: Engineered ball joints and tie rod ends
• Position: Front
• Function: Roll centre correction and bump steer correction
• Weight: 4.6 lbs
• Barcode: KCA313

Fitment Information:

• 2002-2007 Subaru WRX (GD chassis)
• 2004-2009 Subaru WRX STI (GD chassis)
• 2005-2008 Subaru Legacy GT (BP chassis)
• 2008+ Subaru WRX Hatch (GR chassis)
• Note: Designed for lowered vehicles — most beneficial when vehicle has been lowered 30mm or more from factory ride height
• Note: Alignment required after installation — use an alignment shop familiar with Subaru geometry and roll centre correction
• Installation: Professional installation recommended

What's Included:

• Whiteline front roll centre and bump steer correction kit (KCA313)
• Engineered ball joints and tie rod ends
• Note: Refer to Whiteline installation instructions for complete parts list and installation procedure

Installation Notes:

• Professional installation recommended
• Full front suspension disassembly required to replace ball joints and tie rod ends
• Inspect all suspension components while the area is accessible
• Torque all fasteners to Whiteline and Subaru specifications
• Full wheel alignment required after installation — do not drive without alignment check
• Inform your alignment technician that roll centre correction components have been installed — alignment targets may differ from standard lowered vehicle settings

Roll Centre Correction — Why It Matters for Lowered Vehicles:

The roll centre is a geometric point in the suspension that determines how the vehicle's body rolls relative to the road surface during cornering. Every suspension system has a roll centre height that is determined by the geometry of the suspension links — specifically the angles of the control arms and the position of their pivot points. The factory suspension is designed with a specific roll centre height that provides the intended handling balance at factory ride height.

When a vehicle is lowered, the geometry of the suspension changes. The control arms, which were designed to operate at a specific angle at factory ride height, now operate at a different angle — and this change in angle moves the roll centre. On most MacPherson strut and double-wishbone front suspensions, lowering the vehicle moves the roll centre downward — sometimes dramatically. A lower roll centre increases the moment arm between the roll centre and the vehicle's centre of gravity, which increases body roll for a given lateral force. The result is that a lowered vehicle with an uncorrected roll centre may actually handle worse than the factory vehicle in terms of body roll and weight transfer, despite the lower centre of gravity.

Whiteline's roll centre correction kit raises the front roll centre back toward its factory design height by using specially engineered ball joints and tie rod ends with modified geometry. By raising the outer pivot points of the front suspension links, the kit corrects the roll centre height without requiring changes to the suspension mounting points or chassis. The result is a front suspension that operates with the correct roll centre geometry at the lowered ride height — providing the handling benefits of lowering (lower centre of gravity, improved aerodynamics) without the geometry penalties of an uncorrected roll centre.

Bump Steer — What It Is and Why It Matters:

Bump steer is the change in toe angle that occurs as the suspension moves through its travel — as the wheel moves up and down over bumps, the toe angle changes, causing the vehicle to steer slightly without any input from the driver. Some bump steer is present in all suspension designs, but it is carefully minimized in factory suspension geometry by matching the arc of the tie rod end to the arc of the suspension travel. When a vehicle is lowered, the tie rod end operates at a different angle than it was designed for, and the arcs no longer match — introducing additional bump steer that was not present at factory ride height.

Bump steer has several negative effects on handling: it causes the vehicle to track inconsistently over bumps, it can cause the front end to dart or wander mid-corner when the suspension is loaded, and it makes the steering feel less precise and predictable. On a performance vehicle like the WRX or STI, where precise steering response is critical for driver confidence and lap times, bump steer correction is a meaningful improvement that makes the car feel more planted and predictable.

Whiteline's KCA313 corrects bump steer by using tie rod ends with modified geometry that re-matches the tie rod arc to the suspension travel arc at the lowered ride height. The result is a front suspension that tracks consistently through its travel without unwanted toe changes — providing more predictable steering response over bumps and mid-corner.

Subaru WRX/STI and Legacy GT — Suspension Context:

The GD-chassis Subaru WRX and STI (2002-2007/2009) and BP-chassis Legacy GT (2005-2008) use a MacPherson strut front suspension that is sensitive to roll centre changes when lowered. These platforms are extremely popular for performance modification, and lowering springs or coilovers are among the most common upgrades. However, many owners who lower their WRX or STI notice that the handling improvement from lowering is less than expected — or that the car actually feels less composed than before. Roll centre correction is frequently the missing piece that unlocks the full handling benefit of the lowering modification, and the Whiteline KCA313 is one of the most respected solutions for this specific issue on these platforms.

Why Whiteline?

Whiteline is an Australian manufacturer of suspension geometry correction and performance suspension components with decades of experience developing solutions for a wide range of vehicles. Their roll centre and bump steer correction kits are engineered with genuine understanding of suspension geometry and the specific effects of lowering on each platform. Whiteline's KCA313 is a well-established, proven solution for the GD WRX/STI and BP Legacy GT, trusted by performance drivers and alignment specialists worldwide.

Perfect For:

• 2002-2007 Subaru WRX owners who have lowered their vehicle and want to correct roll centre and bump steer geometry
• 2004-2009 STI owners running coilovers or lowering springs wanting maximum front end grip and handling consistency
• 2005-2008 Legacy GT owners experiencing handling issues after lowering
• 2008+ WRX Hatch owners wanting roll centre and bump steer correction for improved cornering performance
• Any lowered GD WRX/STI or BP Legacy GT owner wanting to restore correct front suspension geometry for improved grip, reduced body roll, and more predictable handling

Perfect For: Lowered 2002-2007 Subaru WRX, 2004-2009 STI, 2005-2008 Legacy GT, and 2008+ WRX Hatch owners seeking Whiteline KCA313 front roll centre and bump steer correction for improved front end grip, reduced body roll, and more consistent handling.

Pro Tip: After installing roll centre correction components, have your alignment done by a shop that understands what the kit does and can set alignment targets appropriate for a corrected roll centre — not all alignment technicians are familiar with roll centre correction, and an alignment set to standard lowered-car targets may not take full advantage of the geometry correction the kit provides.

Roll Centre & Bump Steer Correction | Front | Lowered Vehicles: 2002-2007 WRX / 2004-2009 STI / 2005-2008 Legacy GT / 2008+ WRX Hatch. Alignment required after installation. 4.6 lbs. Professional installation recommended.

Restore correct front geometry on your lowered Subaru with Whiteline KCA313 — roll centre and bump steer correction for improved front end grip, reduced body roll, and more consistent cornering on WRX, STI, Legacy GT, and WRX Hatch.